On Jul 15, 4:30 pm, Jeff Liebermann wrote:

Radium hath wroth:

The problem with AM audio is that the ultimate signal to noise ratio
isn't very good. AM is noisy at any signal strength. The noise never
really goes away. On the other foot, FM is noisy with very weak
signals, but becomes very quiet once the limiter starts to work.
That's why FM is preferred for music and why analog AM broadcasting
sounds marginal at any signal level.

AFAIK, the main issue with AM is that it is much more vulnerable to
magnetic disruptions than FM. That is why when you are listening to
the AM radio at home and someone turns on the microwave-oven, you here
those odd sounds on the receiver.

Also, if there is a solar prominence you can hear the resulting
magnetic disruptions on an AM radio receiver. They sound scary and
enjoyable at the same time.

Nope. For decent quality sound you need audio that is uncompressed PCM
[similar to CDs and WAVE files] with a sample rate of at least 44.1
KHz and a bit-resolution of at least 16-bit. Or the analog equivalent.

I thought you didn't like digital? You only gave me a choice of AM or
FM. Now, you want digital.

It depends, if I can find the analog-equivalent of 44.1 KHz-sample-
rate, 16-bit-resolution digital audio, that just as good.

If I a limited to only AM or FM for analog audio, I choose AM because
I like the sounds generated by solar prominences and other RF magnetic
disruptions.

Ironically, for video, I prefer FM. Yup, video signals on FM carriers
instead of AM carrier. The Y-luminance signal should be broadcasted on
an FM carrier. That's the analog video I like.

With compression and
proper coding, you can pickup quite a bit of efficiency, at the
expense of sounding like you're gargling ball bearings.

Disgusting! I hate most forms of digital audio compression. For me,
either keep it uncompressed or use WMA compression. All non-WMA
digital audio compressions below 320 kbps sound like stinky human
fart. Or an angry infant foaming at the mouth.

Not too bad a
tradeoff for voice. Really awful for music.

Awful for both. The only digital audio compression I like is WMA.
The sounds resulting from WMA compression sort of make me think of
those RF electronic telecommunication devices used in The Bourne
Identity. That movie features some really awesome devices that make
those interesting sounds - for example, when the main character is
getting his hand screened. I also associated these sounds with the
electronic telecommunication devices used by the Soviet Union. Soviet
Union has got some really psychedelic sounds in their electronics. You
know, those fancy dial-up modems tones?

Fortunately, none of the
broadcasters or cellular carriers use raw CD data, mostly because it's
not compressed.

All digital audio compression formats other than WMA, stink badly!!

Here are my rules for digital audio:

A. Whether compressed or not, the audio must be monaural and with a
sample-rate of at least 44.1 kHz.

B. The only compression allowed is WMA. No other compression format is
permitted.

C. In its uncompressed form, the audio must have a bit-resolution of
at least 16-bit

D. If compression is used, then the sample-rate of the compressed and
the uncompressed version of the audio must be the same.

E. If compression is used, the only thing that should be decreased is
the bit-resolution. The sample-rate must remain unchanged

Let's say a song that was originally recorded in stereo is given to
me. The song must to be converted to mono* via the following steps:

1. Record audio from CD [or other stereo audio source] into Wavelab,
Adobe Audition [or other audio software] into a file. For simplicity
let's call this file "Track1.wav"

2. Make a copy of Track1.wav and save the copy as "Track1B.wav"

3. Open Track1.wav and reduce the gain of its audio by 77.5%

4. Convert Track1.wav to monaural audio

5. Save Track.1

6. Open Track1B.wav and reduce its audio gain by 50%

7. Invert the phase of the left channel of Track1B.wav

8. Convert Track1B.wav to mono

9. Save Track1B.wav

10. Create a new stereo wave file whose bit-resolution is 16-bit and
sample rate is 44.1 kHz. For simplicity let's call this file
"untitled.wav"

11. Copy and paste the audio of Track1.wav into the left channel of
untitled.wav

12. Copy and paste the audio of Track1B.wave into the right channel of
untitled.wav

13. Convert untitled.wav to mono

14. Save untitled.wav

*Songs that were originally-recorded in stereo need to be converted to
mono via the above 14 steps because different sounds are recorded
differently in the L and R channels. The audio that is originally
panned to the center is significantly louder than the audio whose
phase is different in the left & right channels. This is why I reduce
the loudness of non-inverted stereo audio file by 77.5% [before
converting it to mono].

In the stereo file whose left channel has its phase inverted, I
decrease the loudness only by 50% and then convert it to mono. Usually
-- the lead vocals, bass, and percussion are recorded identically in
both the left and right channels. The piano, chorus, guitar, and synth
pads are usually recorded differently in the left and right channel.